This counter is cleared when a transition is made from one mode (Read, Write or Position) to Read or Write mode

The Filemark counter is a 16-bit counter of filemarks received from the Host (during Write operations) or sent to the Host (as a Check Condition Status when a filemark has been detected on the

tape).

This counter is cleared when a transition is made from one mode (Read, Write or Position) to Read or Write mode.

This counter counts Underruns during Write operations or

Over-runs during Read or Verify operations. The counter is cleared

when a transition is made from one mode (Read, Write or

Posi-tiQn) to Read or Write mode.

TANDBERG DATA

Number of

Recoverable Errors

Marginal Counter

Remaining Blocks

SourcelOestlnation Status Byte

SourcelOestl nation Sense Bytes

9-45 Software Interface

This counter counts Rewrites during Write operations or Rereads during Read or Verify operations. The counter is incremented by J for every block that is rewrinen (1 to 16 times) or for each block that is re·read (l to 24 times).

This counter is cleared when a transition is made from one mode (Read, Write or Position) to Read or Write mode.

This counter is incremented by 1 for every block that is re-read more than 8 times.

This counter is cleared when a transition is made from one mode (Read, Write or Position) to Read or Write mode.

This is the number of unwritten blocks left in the data buffer af-ter a fatal error has occurred during a Write operation.

This status byte is returned from the source or destination device when a data transfer error has been detected during a Copy operation.

In case the Copy operation is performed by a TOC 3620/40/60 Drive, this byte will always read 02H (Check Condition).

These are the Sense Bytes returned from the source or destina-tion device when a data transfer error has been detected during a Copy operation.

In case this device is the Target, the Sense Bytes are the bytes transferred from the Target in response to a Request Sense command issued by the Drive.

The Sense bytes will be in the Standard Sense format when the Copy operation is performed by a

mc

3620/40/60 Drive.

The V ADD· bit is set to zero •

° ..

The information bytes are also set to 0, except for the least sig-nificant byte (byte 27), which holds the Drive's Extended Error Code.

TANDBERG DATA 9-46 Software Interface

The hexadecimal Sense Key Code is defined as follows:

Sense Key

Code Meaning Description

0 NO SENSE There is no specific information. This could be the case if Sense is requested because of File Mark or End

or

Media detected. In these cases the FM or EOM bits will be set.

1 Reserved ^,

2 NOT READY Reports that the cartridge is not inserted andlor loaded.

3 MEDIA ERROR Unrecoverable data error occurred.

4 HARDWARE ERROR Power-up Selftest failed, or parity error detected.

5 ILLEGAL REQUEST Illegal parameter detected in the Command Descriptor Block or in additional parameters supplied as data.

S UNIT AITENTICN A Unit Attention Condition occurred. (See Section 7.5.2). This status indicates that the cartridge has been removed since the last com-mand. It is retumed the first time a command is given after the cartridge has been removed.

The condition is cleared for the next command from the same Initiator. Unit Attention is given to all SCSI-devices that subsequently issue a command to the Drive.

7 DATA PROTECT Retumed if writing is requested to a write pro-tected cartridge.

S BLANK CHECK the logical End

or

Media (end of recorded area) is detected.

9 Reserved

A COpy ABORTED A Copy command was aborted because an error condition was detected on the source or desti-nation device.

B ABORTED COMMAND The Drive aborted the command. The Initiator may recover by trying the command again.

C Reserved

Table to be continued on the next page:

TANDBERG DATA 9·47 Software Interfar:e

Sense Key Code Table continued:

Sense Key

Code Meaning Description

0 VOLUME OVERFLOW This condition can OCOJr " additional data blocks are appended after the Drive has reponed EOM, and there is not sufficient space left. If this error situation occurs, the non written blocks can be reclaimed by issuing the Recover Buffered Data command.

E MISCOMPARE Used by the Verify command to indicate that source data did not match the data read from the tape.

F Reserved

TANDBERG DATA 9-48 Software Interface

I

9.3.15. Reserve Unit (16H)

BYTE BIT 7 6 5 4 3 2 1 o

00 0 0 0 1 0 1 1 0

01 Logical Unit Number

I

^THP Third Party 10

I

⁰

02 03 04

05 X

Reserved Reserved Reserved

I

^Reserved

¹

^Flag

¹

^Link

This command reserves the Drive for the requesting Initiator un-til a Release Unit command from the same Initiator occurs.

During this time no other Initiator can use this drive.

If a command is received from another Initiator while the Drive is reserved for one Initiator, the Drive will send a RESER V A-TION CONFLICT status and disconnect from the requesting Initiator.

THP (Third Pany The Third Pany Reservation option (Byte I, Bit 4) allows a Reservation option) LUN to be reserved for another device. If this bit is set, an

Ini-tiator is allowed to reserve the Drive for the SCSI-bus device specified in the Third Pany 10 field (Byte I, Bits 1 to 3). This option is intended for multiple-host environments where the Copy command is used. The Drive stays reserved until it is re-leased by the same Initiator that reserved it.

Third Party 10 The three bits (Byte I, Bit 1 to 3) specify the SCSI-bus device 10.

The Drive does not disconnect during the execution of this command.

TANDBERG DATA 9-49 Software Interface

19.3.16. Rewind (01 H)

BYTE BIT 7 6 5 4 3 2

,

00 0 0 0 0

I

⁰ ⁰ ⁰

,

01 Logical Unit Number

I

^Reserved ^liMED

02 03 04

05 X

IMED

Reserved Reserved Reserved

I

^Reserved

I

^Flag

I

^Link

This conunand will rewind the tape to BOT.

If the IMED bit is set the command will return status as soon as the rewind is initiated. If lMED is not set, status will not be re-turned until the tape has stopped at BOT. If the IMED option is used and a new command is received during the rewind opera-tion, that command will be executed immediately after the rewind is completed. If the lMED bit is set the LINK bit must be zero - 0 - or else a Check Condition Status will be returned with the Sense Key set to Illegal Request and the Sense Code to In-valid Command.

The Drive may disconnect during the execution of this com-mand.

TANDBERG DATA 9-50 Software Interface

19.3.17. Seek Block (OCH)

BYTE BIT 7 6 5 ⁴ ³ ²

,

00 0 0 0 0

I

¹ ¹ ⁰ ⁰

01 Logical Unit Number

j

^Reserved ^liMED

02 03 04

05 X

IMED (Immediate)

Reserved

I

Block Address (MSB)

Block Address Block Address (LSB)

I

^Reserved

I

^Flag

I

^Link

The Seek Block command causes the Drive to position the tape at the specified block address. No data is transferred.

The Initiator may obtain block addresses via the Request Block Address command as part of its tape write procedures. The block address can, in turn, be recorded in a user-defined directory.

Typically, this directory is located at the end-of-recorded-data and is used to rapidly position at the beginning of specific files on the tape. The Space command can be used to position the tape at the End of Recorded Area - and then by issuing Space Reverse One File Mark - to the position in front of any directory blocks.

A block address if zero - 0 - will cause Check Condition Status with the Sense Key set to Illegal Request and the Error Code to Invalid Command.

If

the specified block address is not found on the tape. a Check Condition Status is returned and the Sense Key will repo" Blank Check while the Error Code will be set to No Record Found.

The IMED bit is used to request that status be returned as soon as the operation is initiated. When the IMED bit is not set, status will be returned after the tape is positioned at the specified block. If the IMED bit is set the LINK bit must be zero - 0 - or else a Check Condition Status will be returned with the Sense Key set to Illegal Request and the Sense Code to Invalid Com-mand.

The Drive may disconnect during the execution of this com-mand.

TANDBERG DATA

9-51 Software Interface

I

9.3.18. Send Diagnostics <1 DH)

6 5 3 2 ¹ o

0 0 1

I

¹ ¹ ⁰

^,

LUN .. 0

I

⁰

I

^STest

I

^OevOfI

I

^UniOIi

Reserved

Parameter List Length (MS8) Parameter List Length (LS8)

I

^Reserved

1

^Flag

J

^Link

The Send Diagnostics command requests the Drive to perform diagnostic tests on itself (so-called Self tests). Two different types - Self test 1 and Self test 2 - may be requested:

- Default Self test 1 is similar to the Power-on Self test and involves no tape Read- or Write operations. See Section 10.1.1 for test description.

- Default Self test 2 - which is identical to the Acceptance Test - is a more thorough self test involving both Read- and Write operations. See Section 10.1.2 for a test description.

Self test 2 may be run with default parameters or with special parameters sent to the Drive as a Parameter Block.

To run this test an unprotected cartridge must be insened and loaded.

The command will return with GOOD status if no errors occurs.

Else, Check Condition will be set. By issuing a Request Sense command, the Extended Sense Block will give information about the problem. The EXERCD-byte will suppon the detailed information. See Appendix A for explanation of the different EXERCD-error codes.

When the STest bit is set to ONE, ~ 1 - , the Drive will perform one out of two possible self tests (Self test 1 or 2) using default test parameters.

If the STest bit is set to ZERO, - 0 - , the Drive will expect a pa-rameter Jist with papa-rameters for Self test 2. If there is no parame-ter list, no operation is performed.

When STest default is set, either one of DevOfl or will select one out of the two self tests with parameters:

1) If both DevOfl and UniOfl are set to ONE, the default Self test 2 is selected.

2) If either DevOfl or UniOn are set to ZERO, .the default

Self test 1 is selected. .

When STest is set to ZERO, both DevOfl and UniOfl must be set to ONE. If not, the Drive will respond with Check Condition status with the Sense Key set to TIlega! Request.

TANDBERG DATA

The Self tests are described

detail in Chapter 10. Self test and Preventive Maintenance.

The table below shows the Parameter Block:

6 4 3 2 1 o

Acceptance TestlSelftest 2 can be run with changed parameters.

This is basically the same test as the Self test 2 described in Section 10.1.2. The difference is that

is possible to alter the test parameters in the Parameter Block above. The parameters that can be changed are:

- No. of Tracks to test Range: > 0 < 255

Dans le document == TDC 3600 SERIES (Page 125-133)